Explosives

Hazards of storing propellant powders

Propellant Powders (Smokeless and Black)are common items in the shooting industry but are hazardous substances due their ease of initiation and flammability.  At times we find that these substances have been stored in less than ideal conditions, and quite often in secondary containers (milo tins, food containers etc.).

It is well known that ammunition can deteriorate with age to a stage where it will not reliably fire. It is not widely known that propellant powder deteriorates and decomposes with age. A retardant is added to powder to stop or delay decomposition. However, in time, the retardant loses its effectiveness, decomposition sets in a spontaneous combustion can occur.

There have been several incidents involving fire and deteriorated or incorrectly stored propellant powder.

Below is a list of those incidents and suggested control measures to prevent them similar incidents reoccurring.

Previous incidents

• A young boy received 60% burns to his body when the muzzle flash from his rifle ignited a poorly sealed drum containing 2kg of 25-year-old propellant powder.
• A man received serious burns to his arm and upper chest when a bag of gunpowder ignited from sparks from an angle grinder he was using. The man was unaware of the powder, as it was stored in an unlabelled calico bag and was at least 50 years old.
• Propellant powders aged 15 to 20 years old were stored in a gunroom safe and appeared to spontaneously combust while stored. This resulted in a fire and subsequent explosion due to confinement. The safe door bulged out and the brick wall adjacent to the safe was badly damaged due to the explosion.

Suggested control measures

• Ensure you adequately rotate stock rotation to use old powders first.
• Use the product within the shelf life recommended by the manufacturer. If you don’t know the recommended shelf life, use a maximum shelf life of 10 years.
• Purchase a quantity of powder that matches the usage rate.
• Store in original containers in a cool, dry, well-ventilated place away from all sources of ignition.
• Dispose of old powders in an appropriate manner. Refer to the Safety Data Sheet applicable to the propellant powder.
• Call an Explosives Inspector on 1300 739 868 to collect and dispose of powders at no charge.